The present invention relates to an inductor coil structure and method for making same. The coil structure of the present invention is preferably for use in a high current low profile inductor commonly referred to by the designation IHLP. However, the particular coil structure may be used in other types of inductors.
Inductor coils have in the prior art been constructed from various shapes of materials formed into various helical shapes. However, there is a need for an improved inductor coil structure which is simple to manufacture and which provides an efficient and reliable inductance coil.
Therefore, a primary object of the present invention is the provision of an improved inductor coil structure and method for making same.
A further object of the present invention is the provision of an inductor coil structure which can be used in a high current low profile inductor having no air spaces in the inductor, and which includes a magnetic material completely surrounding the coil.
A further object of the present invention is the provision of an inductor coil structure which includes a closed magnetic system which has self-shielding capability.
A further object of the present invention is the provision of an inductor coil structure which maximizes the utilization of space needed for a given inductance performance so that the inductor can be of a minimum size.
A further object of the present invention is the provision of an improved inductor coil structure which is smaller, less expensive to manufacture, and is capable of accepting more current without saturation than previous inductor coil structures.
A further object of the present invention is the provision of an inductor coil structure which lowers the series resistance of the inductor.
The foregoing objects may be achieved by a high current low profile inductor comprising a conductor coil having first and second coil ends. A magnetic material surrounds the conductor coil to form an inductor body. The inductor coil comprises a plurality of coil turns extending around a longitudinal coil axis in an approximately helical path which progresses axially along the coil axis. The coil turns are formed from a flat plate having first and second opposite flat surfaces, at least a portion of each of the flat surfaces of the coil turns facing in a axial direction with respect to the coil axis.
The method for making the inductor includes taking an elongated plate conductor having a first end, a second end, opposite side edges, opposite flat surfaces, and a longitudinal plate axis. A plurality of slots are cut in each of the opposite side edges of the plate conductor so as to form the plate conductor into a plurality of cross segments extending transversely with respect to the plate axis and a plurality of connecting segments extending approximately axially with respect to the plate axis. The connecting segments connect the cross segments together into a continuous conductor which extends in a sine shaped path. As used herein the termxe2x80x9csine shapedxe2x80x9d refers to any shape which generally conforms to a sine curve, but which is not limited to a continuous curve and may include apexes, squared off corners or other various shapes.
After cutting the slots in the opposite side edges of the plate conductor the connecting segments are bent along one or more bend axes extending transversely with respect to the plate axis so as to form the plate conductor into a plurality of accordion folds, each of which comprise one of the cross segments and a portion of one of the connecting segments. In the resulting structure, the cross segments and the connecting segments form a continuous conductor coil of approximate helical shape having first and second opposite ends.